How to initialize an array variable inside a structure?

Question

I want to initialize a couple of arrays which are members of a struct which is passed to a function by reference. Appreciate any help.

typedef struct Snake_pos
{
    char field[10][10];
    int Y[10];
    int X[10];
}snake_pos;

int main()
{
    snake_pos pos1;
    pos_init(&pos1);
    return 0;
}

void pos_init(snake_pos *pos1)
{
    pos1->X={};
    pos1->Y={};
    pos1->field={};
}

Answer 1

You can only use the syntax = {} when defining the variable. So to zero every member you can either define it as

snake_pos pos1 = { 0 };

Or if it is passed to a function, like this

void pos_init(snake_pos *pos1)
{
    memset(pos1, 0, sizeof *pos1);
}

Answer 2

You can access any array element inside of an array through a structure pointer this way :

• for 1 D array : structure_pointer->array_valiable[index1]
• for 2 D array : structure_pointer->array_valiable[index1][index2]

---

so now, you can initialize each member of arrays X , Y and field of structure snake_pos using scanf() this way :

#include <stdio.h>

typedef struct Snake_pos
{
    char field[10][10];
    int Y[10];
    int X[10];

}snake_pos;

void pos_init(snake_pos *pos1)
{
    int i,j;

    //initializing each member

    //of array X
    for(i=0;i<10;i++)
        scanf("%d",&pos1->X[i]);

    //of array Y
    for(i=0;i<10;i++)
        scanf("%d",&pos1->Y[i]);

    //of the two dimensional array field
    for(i=0;i<10;i++)
        for(j=0;j<10;j++)
            scanf(" %c",&pos1->field[i][j]); 
    //notice the space before %c is to consume white spaces returning from before scanf's
}


int main()
{


      snake_pos pos1;
      pos_init(&pos1);

  return 0;
}

---

Note : if you want to initialize all members to a single fixed value, then you can instead of using scanf() in for loop, assign the value this way :

  for(i=0;i<10;i++) //initializes all members with a value of 0
      pos1->X[i]=0;